梯田玉米有机肥最佳施用量的研究

施用２种有机肥（羊粪、猪粪）,并配施少量化肥,进行雨养梯田种植玉米的田间试验,结果表明,施有机肥后土壤总孔隙度、毛管孔隙度分别提高５．２％～１３．１％和３．６％～１０．０％,土壤容重降低１．８％～７．９％;雨后土壤含水量提高９．８％～１５．３％;玉米平均株高、平均茎粗分别增加０．１～６．５ｃｍ和０．１～０．５ｃｍ,玉米产量提高３３．５％～７７．２％。玉米产量与有机肥施用量呈３次方关系,并由此确定了     

镁锌硼肥在烤烟生产中应用效果的研究

在临沂市自然条件下，烤烟增施镁、锌和硼肥，可使烟叶产量提高１２．７－１６．６ｋｇ／亩，上中等烟叶的比例增加２．５－５．９个百分点，烟叶均价提高０．１４－０．２６元／ｋｇ，亩增加纯收益６１．２－７４．５元。同时，烟叶的品质得到明显的改善，烟碱含量增加，施木克值提高，总氮和氯离子含量下降；烟叶的香气增加，吃味醇和，评吸总分提高２．６－４．１分。     

豫东潮土区小麦施钾技术与应用

在施用一定量氮、磷肥及有机肥基础上增施钾肥，小麦增产显著或极显著。钾肥一次掩底或返青期及早追施效应最好；亩产３５０－５００ｋｇ适宜的施钾量６－１０ｋｇＫ２Ｏ；中低区及高产区适宜的氮磷钾配比（Ｎ：Ｐ２Ｏ５：Ｋ２Ｏ）分别为１：０．４－０．６：０．４－０．５及１：０．６－０．７５－０．９５；土壤速效钾（Ｋ２Ｏ）含量＜１００ｍｇ／ｋｇ钾肥有效；砂土、两合土、亩产５００ｋｇ高产田及晚播麦田为施钾高效类型区，     

营养液pH对小麦生长及吸收铵、硝态氮的影响

采用３种起始ｐＨ不同的营养液进行水培，研究介质ｐＨ对小麦吸收铵、硝态氮及生长量的影响。结果表明，小麦生长期间营养液的ｐＨ因起始值和生育期而变化；这种变化与铵、硝态氮的相对吸收量密切相关。在铵、硝态氮等量共存条件下，介质ｐＨ低有利吸收硝态氮；高、有利吸收铵态氮。起始ｐＨ为５．０、６．５和８．０的营养液，铵，硝态氮的平均吸收比例分别为０．６１、０．９４和１．８５，累积吸收的铵态氮分别占吸氮总量的３３．     

不同施肥量烤烟钾素营养效应

应用＾８６Ｒｂ研究不同施肥量烤烟钾素营养效应,结果表明：随着施钾量的增加,在烤烟打顶期,烟叶中Ｋ２Ｏ含量,每株烤烟施２．５ｇ,１．５ｇ,２ｇＫ２Ｏ分别比对照增加１８．７５％,１７．４３％和３．２９％,每株烤烟吸收肥料中Ｋ２Ｏ量,施３ｇＫ２Ｏ时分别比施１．５ｇ,２ｇ和２．５ｇＫ２Ｏ增加１９．７４％,１３．５７％和１３．０１％每株烤烟吸收总Ｋ２Ｏ量,施２．５ｇＫ２Ｏ分别比ＣＫ,施１．５ｇ和２ｇＫ２Ｏｆ     

钾用量与灌溉方式互作对土壤-烤烟系统钾素及烟叶品质的影响

旨在探究钾用量与灌溉方式互作对土壤-烤烟系统钾素变化及烟叶质量的影响问题。采用大田裂区设计,研究了不同灌溉方式与钾用量互作对土壤-烤烟系统钾素及烟叶内在化学成分的影响。同一灌溉方式下,增施钾肥显著提高土壤钾素含量,土壤速效钾和缓效钾含量随钾肥用量的增加而增加;与不施钾相比,施钾显著提高烟叶钾含量,但常规施钾与高量施钾处理间烟叶钾含量差异不显著。相同施钾量下,3种灌溉方式相比,以交替对1/2区域灌水处理土壤速效钾和缓效钾含量最低,烟叶钾含量以固定对1/2区域灌水处理最高,但与交替对1/2区域灌溉处理差异不显著。烟叶采收结束时,9个处理的土壤速效钾含量均随土层深度的增加,呈先降低再增加的趋势,至60~100 cm土层趋于稳定。灌水方式和钾用量互作对烟叶化学成分有一定影响,以常规施钾与固定1/2区域灌水处理组合的烟叶化学成分协调性最佳。在常规施钾量下,固定1/2区域灌水处理不仅改变了钾素在不同土层的分布,而且提高了烟叶钾含量,且减少了灌溉用水,建议可在黄淮烟区进行示范应用。     

灌溉条件下施氮水平对土壤 作物系统中肥料氮素去向的影响

本试验利用１５Ｎ示踪技术，研究３种施氮水平（适宜施氮量Ｎ１０∶１５０ｋｇＮ·ｈａ－１，低于适宜施氮量的５０％Ｎ０５∶７５ｋｇＮ·ｈａ－１，高于适宜施氮量的５０％Ｎ１５∶２２５ｋｇＮ·ｈａ－１）对灌溉冬小麦氮素利用、去向及作物产量的影响。结果表明：在灌溉条件下，３种施氮水平（Ｎ０５，Ｎ１０，Ｎ１５）的冬小麦氮素利用效率分别为３８５％、３２３％和２２４％，以Ｎ０５水平为最高。Ｎ１０施氮水平获得了最高的作物产量（６８０×１０３ｋｇ籽粒·ｈａ－１，１４７×１０３ｋｇ生物量·ｈａ－１），Ｎ０５水平同Ｎ１０水平相比，在产量上没有显著性差异；而Ｎ１５水平因施氮过量造成籽粒产量明显下降，与不施肥相比，差异不显著。在深层条施（５～８ｍｍ）条件下，仍有３０２％～３６７％的化学氮素通过各种途径而损失。在Ｎ１５水平中，施用氮素的４６％仍存在于０～５０ｃｍ土层中，远远高于其它两种施肥水平。土壤残留态的无机氮素含量以Ｎ１５施氮水平为最高     

土壤-烤烟矿质营养元素相互关系的主组分分析

对云南五种植烟土壤上烤烟三个品种、六个生育期烟叶中钾、磷、硫、钙、镁、铁、锰、锌、铜、硼浓度和烟株根区土壤中ＡＢ／Ｄ联合提取的养分含量及土壤ｐＨ、有机质和碱解氮的测试数据，用主组分分析（ＰＣＡ）方法，讨论土壤─烤烟系统矿质营养元素的相互关系及交互作用。结果显示：①烟叶矿质营养元素浓度随烤烟生育期有规律的变化，受根区土壤化学性质影响的变异大于品种间的差异；②烟叶钾、磷、铜、硼表现明显的稀释效应，钙、镁表现积累效应；③烤烟钾、磷、铜、硼营养存在相互协同作用，钙对钾、磷、铜、硼营养有明显的拮抗作用。④增加土壤有机质，利用钾、磷、铜、硼的协同作用，减轻钙对钾、磷、硼的拮抗是改善烤烟营养，提高烤烟产量品质的关键之一。     

陕西渭北旱塬烤烟施用钾肥技术研究

在渭北旱塬进行烤烟钾肥篱用量试验和氮磷钾肥配比试验,结果说明施钾肥可以提早旺长期,增加干物质积累,提高上中等烟比例和含钾量。在目前的土壤速 效钾水平下,旱塬施钾不应超过Ｋ２Ｏ１８０ｋｇ／ｍ＾２。在施氮６０ｋｇ／ｈｍ＾２的情况下,氮磷钾肥以１：２：３（Ｎ：Ｐ２Ｏ５：Ｋ２Ｏ）配合可达到较高的产量和产值,烟叶含钾量提高到２％以上。     

陕西省红富士苹果果园施肥调查

对陕西省红富士苹果果园施肥调查表明，追求产量，超量施肥比较普遍，各县之间果园施肥水平差异很大，用肥比例不合理，低钾和不施钾的占７７％，初挂果和盛果期果园氮磷钾（Ｎ、Ｐ２Ｏ５、Ｋ２Ｏ）用量，以每亩３０－５０ｋｇ为宜，有机肥３０００－５０００ｋｇ，用肥比例Ｎ：Ｐ２Ｏ５：Ｋ２Ｏ为１：０．５－１：０．６－０．８。     

高钾用量和根区施肥可提升皖南不同质地土壤烟叶钾含量

钾是烟叶的品质元素之一,提升烟叶钾含量一直是我国烟草行业关注的重点之一。本文选取安徽烤烟主产区皖南宣城市砂土与黏土两类典型土壤,以云烟97为试验材料,研究田间条件下不同高钾用量水平与施肥方式对烟叶钾含量的影响。研究结果表明,在耕层土壤全层混施方式下,随着施钾量增加(0、300、600、900、1 200、1 800、2400mg/kg,以纯K计),两种质地土壤烟叶钾含量均显著上升,呈先快速增加而后缓慢增加的趋势。在钾肥用量低于1 200 mg/kg时,每增加钾肥用量100 mg/kg,砂土和黏土烟叶不同部位钾含量分别平均增加2.4 g/kg和1.0 g/kg。更高钾肥用量可使砂土烟叶钾平均含量提升到44.0 g/kg,黏土则只能提升到26.2 g/kg。两类土壤钾肥效果差异极大的原因与土壤固钾能力有关,土壤速效钾含量与烟叶钾含量呈线性相关,而黏土钾肥固定率平均为71%,远高于砂土的25%,这是两种质地土壤钾肥肥效差异的根本原因。在常规同等钾肥用量条件下(K2O25kg/667m2),氮磷钾根区集中施用较常规条施显著促进了烟叶对钾的吸收,提升了烟叶钾含量,而且砂土的效果要好于黏土,其原因也与根区施肥可显著提升烟叶根区土壤速效钾含量有关。以上结果表明,选择固钾能力弱的土壤,提高钾肥用量并改进施肥方法可以有效提升皖南烟叶钾的含量。     

湖南烟区土壤含氯状况及烤烟施氯效应

对湖南省主要烟区3329个土壤样品中水溶性氯含量的测定结果表明,湖南省主要烟区土壤水溶性氯含量平均为16.6.mg/kg,在烤烟生长适宜的含氯范围内。不同烟区土壤中水溶性氯含量差异较大,湘西、湘中烟区,水溶性氯含量较低的土壤所占比例较大。田间试验表明,适量的氯素营养有利于提高烤烟旺长期叶片中的叶绿素含量和植株根系活力,提高烤烟生长前期Nrase的活性;在氯含量较低的土壤上,施入烟草的钾肥总量中,氯化钾所占比例为15%～30%时(以K2O计),烟叶可增产5.2%～16.9%,产值增加1911.0～7348.5元/hm2,中上等烟比例提高10.2～11.5个百分点,烟叶的品质也得到改善,不会造成土壤氯的积累。在湖南省乃至南方一些土壤氯含量较低的地区,在烟草上可考虑适当施用一定量的氯化钾部分代替硫酸钾,以降低肥料投入成本,提高烟叶的经济效益。     

河南主要植烟土壤养分状况与施肥对策

在河南省不同生态类型区典型地块采集大量土壤和烟叶样品进行分析化验 ,结果表明 :河南省主要植烟土壤的 pH介于中性—微碱性范围 ,有机质和有效氮含量中等偏高 ,大部分土壤有效磷含量偏低 ,有效钾含量较高 ;中量元素钙含量过高 ,最高含量达 4 0 66mg/kg,钾钙关系失调 ;微量元素中锌较缺乏 .烟叶品质突出表现为钾素中等偏低 ,氯离子含量偏高 .为此提出该区烟草施肥中应掌握“稳氮、增磷、补钾、控钙、降氯、配微”的施肥对策     

Beziehung zwischen dem durch K-Düngung erzielbaren Mehrertrag und dem K-Gehalt der Böden nach Feldversuchen in der Bundesrepublik Deutschland

Relationship between the maximum yield increase from K fertilization and the K content of the soils after field trials in the Federal Republic of Germany Several hundred long term potassium field experiments with crop rotation and with plant residues like straw and sugar beet leaves removed from the fields, on different soils of the FRG were evaluated. The K content in the top soil was determined by the DL and CAL methods (K(lact)), given in mg K₂O/100g soil. No relationship could be found between K(lact) and the maximum possible yield increase for wheat, barley, sugar beets, and potatoes, if K(1act) was >5 mg/100g. It seems unnecessary, therefore, raise the K content of the soils. Occasional significant positive yield response should be less emphazised than average yields. Economical average yield increases on K fertilization were found with sugar beets and potatoes, rarely with barley but never with wheat. In all longterm trials the K amount of fertilizer required for maximum possible yield increase was above the amount of K removed by the crop. 7 to 27year field trials on clayer soils show that the K content of the soil may drop to 5-10mg K20(CAL) without causing increased yield response to K fertilization. The yield responses to K fertilizer are dependent to a high degree on the season (weather conditions), as was shown by high yield increases in exceptionally dry seasons. The large content of plant available Kin the top soils was due to high K fertilization during the past decades and the illitic nature of the soils. From the results of the field trials it may be concluded that an amount of K fertilizer which replaces K removed by the crop is sufficient for all soils with 5-10mg K₂O; for > lOmg K₂O(lact) K fertilization can be less than actual K removal. Because of large variations, the K(lact) figures (chapter 5),are of very limited value for predicting fertilizer requirements. The average K fertilizer consumption used (1981/82) of the FRG was higher than the K removed from soils by 79 kg K₂O/ha (in 1982). Official recommendations of K fertilizer in the FRG as well as the amounts of K actually applied are both in disagreement with the results of fertilizer experiments in the field.     

红壤性水稻土上钾肥运筹对烤烟产量和品质的影响

利用田间小区试验研究了南方红壤性水稻土上K肥用量及基追肥比例对烤烟的施用效果。试验结果表明:相同追肥比例下,烟叶产量、产值为施K(K2O)量270 kg／hm2最高,315 kg／hm2最低;总N和烟碱含量随K肥用量增加而极显著减少(r=-0．99***,r=-0．97***,P<0．001)。相同K肥用量下,烟叶产量基追肥比3:7 最高,5:5最低:上等烟比例、均价、产值、烟叶含K量随追肥比例增加而显著提高。因此,在速效K含量为130 mg／kg的红壤性水稻土上,选择适当的K肥用量,增加追肥比例,能更好发挥K肥的施用效果,提高烟叶含K 量,改善烟叶品质。本试验以施K量270 kg／hm2,基追肥比例3:7为最优组合。     

Inhibitory effects of acidic minesoil on the sericea lespedeza/Bradyrhizobium symbiotic relationship 1

Effects of acidic minesoil on sericea lespedeza [Lespedeza juncea (L.F.) var. sericea (Mig.)] and its nitrogen (N₂)‐fixing symbiotic relationship with Bradyrhizobium spp. were examined. Sericea lespedeza was grown in pots with N fertilization, without N fertilization, or with commercial Bradyrhizobium as a seed inoculant. Minesoil (pH 5.2) was fertilized with calcium (Ca), phosphorus (P), molybdenum (Mo), and potassium (K), and the pH level was adjusted to 4.8 or 4.5 with aluminum or iron sulfate [Al₂(SO₄)₃; Fe₂(SO₄)₃]. Minesoil was also limed to pH 6.1. Shoot dry weights, shoot N concentrations, nodule dry weights, and nodule numbers were significantly lower (P < 0.05) when inoculated plants were grown in soil at pH 4.5 and 4.8 compared to limed soil. Thus, the N₂ fixation process was adversely affected below pH 5.0. Nitrogen‐fertilized plants grew well in acidified soil, and there were no significant differences in shoot dry weights of such plants among the soil acidification treatments including limed soil. Thus, the N₂‐fixing symbiosis appeared to be more sensitive to acidified soil than the plant host. The effects of Al toxicity versus other factors could not be determined because Al₂(SO₄)₃‐ and Fe₂(SO₄)₃‐amended soils contained similar levels of toxic Al at the highest pH (4.8) that prevented N₂ fixation.

Time periods required for cells of Bradyrhizobium strains to multiply by a factor of 10⁴ were significantly longer (P ≤ 0.05) in extracts of Al₂(SO₄)₃‐amended soil (pH 4.8 and 4.5) than in extracts of calcium carbonate [CaCO₃]‐amended soil (pH 6.1). These increases suggested that reduced multiplication of Bradyrhizobium in acidified minesoils may have been at least partially responsible for the large decreases in nodulation and N₂ fixation observed in these soils. It was also reasoned that the inability of existing bacteria to infect and nodulate plant roots may also have been a factor, based on the high inoculation rates used and the abilities of Bradyrhizobium cells to survive and multiply (albeit at a reduced rate) in extracts of acidified soil. Sericea lespedeza is known to tolerate soils of pH 4.5. However, results of this study suggested sericea lespedeza may not fix appreciable N₂ in acidic soil below pH 5 when inoculated with commercial Bradyrhizobium, even after the establishment of lespedeza plants tolerant of such conditions.     

湖南烟区土壤K、Mg营养及其施肥效应

通过对湖南主要烟区3520个土壤样品中K、Mg含量测定的结果表明,湖南省主要烟区植烟土壤的全K、速效K、交换性Mg的含量平均分别为13.7gkg-1、127.3mgkg-1、1.16cmolkg-1;不同烟区其含量差异较大,绝大多数土壤存在着不同程度的缺K、缺Mg状况。田间试验表明,钾、镁肥合理配施(K20360kghm-2、MgS04.7H20300kghm-2)能促进烟草生长,增加烟叶产量、产值,提高烟叶品质,促进烟叶对K、Mg养分的吸收。     

改土物料混用对酸性土壤pH和烤烟生长及物质积累的影响

为明确不同酸碱度生物有机肥配施石灰、绿肥改良酸性植烟土壤的效果,本研究采用盆栽试验,研究了石灰(T1)、石灰+绿肥(T2)、酸性生物有机肥+石灰+绿肥(T3)、碱性生物有机肥+石灰+绿肥(T4)等组成的4种不同改土物料组合对酸性植烟土壤pH值、烤烟生长和干物质与氮磷钾积累分配的影响。结果表明,酸性植烟土壤施用不同改土物料组合,可使土壤pH值提高0.79~1.12,改善烤烟农艺性状,促进烤烟根系生长,使烟叶SPAD值增加0.42~2.76,烟株干物质积累提高18.05%~61.42%;除T3外,烟株氮积累总量提高1.42%~14.07%;磷积累总量提高29.76%~98.08%;钾积累总量提高22.48%~105.47%;同时促进了干物质与钾向烟叶中分配。与其他处理相比,石灰和绿肥配施碱性生物有机肥(T4)更有利于提高酸性土壤pH值,有利于烤烟干物质和氮、磷、钾养分的积累;但石灰和绿肥配施酸性有机肥(T3)更有利于增加烤烟根系数量,有利于增加氮、磷、钾养分在烟叶中的分配比例。本研究表明石灰、绿肥和生物有机肥配合施用可提高酸性土壤改良效果,以石灰+绿肥+碱性生物有机肥最好,其次是石灰+绿肥+酸性生物有机肥。本研究结果为湖南省湘西酸性植烟土壤改良提供了理论依据。     

钾肥对烤烟体内钾素分配及微量元素含量的影响

本文用三种典型的植烟土壤研究了不同的钾肥用量对烟株含量及分配的影响，结果表明，烟叶含钾量随钾肥用量的增加而增加，两者符合二次曲线的关系。充分供钾时，钾在烟株体内的含量顺序为芽＞叶＞茎＞根，烟叶不同部位为下部＞中部＞上部；当烟株缺钾时，上部烟叶含钾量高于中下部。无率在哪种土壤上，钾在烟株中的分配比例顺序为烟叶＞茎＞根＞芽，当中部烟叶含钾量达到２．４％时钾在烟株中的分配趋向一稳定值，即在烟叶、茎、根、     

Formation of alkali soils by neutral salt solutions

It has been reported that large tracts of land under irrigation in the western part of United States contain enough soluble salts to depress crop production and thousands of acres have been abandoned because of salinity. In soils commonly called white alkali soils, containing accumulation of neutral salts in the form of chlorides or sulphates, 0.2% of salt will reduce yields of salt sensitive plants and 1.0% will cause marked yield reduction in most crops. If the drainage is poor and water table is maintained near the surface of the soil, evaporaLion will be high and the salt will accumulate. When large amount of soluble salts accumulate at the surface, the soil is termed as saline and has a pH value below 8.5. The soils containing alkali salts such as Na.COa or NaHC03 and having a pH value above 8.5 are called alkali soils or black alkali soils. Misra (1954) has reported that a gradual replacement of calcium ions and a subsequent increase in the exchangeable Na or K in the exchange complex of the soil, due to repeated leaching of the soils with dilute salt solutions of Na or K takes place which is similar to the repeated leaching of agricultural fields by irrigation.al water containing smaller amounts of soluble salts of Na or K. He has also reported that K-soils, which are also alkaline, are formed under similar conditions of leaching of the soil with K-salLs. Greater amounts of calcium were found in the filtrate when soluble salts were used instead of water alone for leaching the soil.